Patients seen at the emergency department (ED) of a hospital complaining of chest pain have varying levels of complication risk in the acute phase of treatment, usually identified as the first 72 hours from when the affliction first occurs. Similarly, cardiac risk screening and monitoring is often done in ambulances, clinics, wards, ICUs and even from home. In the ED, triage is carried out to assess the severity of the incoming patient's condition and to assign appropriate treatment priorities. Early stratification of risk improves treatment strategies as well as assists with the formulation of proper monitoring for the patient. Risk stratification is necessary in EDs as medical resources, such as doctors, nurses, monitoring systems, monitored beds, resuscitation facilities, intensive care units, etc., are never sufficient for all incoming patients to be attended to instantaneously. For example, in the United States, approximately 6 million patients present with chest pain to the ED each year, which makes chest pain one of the leading principle diagnoses during ED visits. Similarly, early identification of high risk patients can benefit management in ambulances, clinics, wards, ICUs and even for home monitoring. Chest pain severity ranges from self-limited to severe and life threatening situations such as cardiac arrest and lethal arrhythmias. The need to identify high-risk patients allows for timely intervention for preventable and treatable complications.
In the past few decades, scoring systems have also been developed, and are now widely used in intensive care units (ICUs) to predict clinical outcomes and assess the severity of illnesses. Some of the systems which have been developed are for example, Acute Physiology and Chronic Health Evaluation (APACHE), Simplified Acute Physiology Score (SAPS) and Mortality Probability Model (MPM). Each scoring system has a specific purpose and its own range of applications. For example, risk of death, organ dysfunction assessment and severity of illnesses are possible outcomes of some of these scoring systems.
The development of scoring systems relies on the appropriate selection of variables or parameters with which prediction outcomes are associated. Present triage tools and risk-stratification systems for patients with suspected acute coronary syndromes (ACS) are based on a combination of traditional clinical factors such as patient medical history, cardiac bio markers, and measurements obtained from ED incoming patient screenings, for example observing and obtaining traditional vital signs such as heart rate, respiratory rate, blood pressure, temperature, and pulse oximetry. However, these parameters have not been shown to correlate well with short or long-term clinical outcomes.
Presently, although thrombolysis in myocardial infarction (TIMI) risk score is currently the most clinically accepted risk categorization of patients with ACS, its prediction accuracy is debatable and perhaps somewhat controversial. There are as such limitations to current risk scores for prediction of cardiovascular complications, whilst at the same time, clinical judgment is subjective, as well as being hampered by a limitation in doctoral resource.